Blast furnace stove



y 1939. o. R. RICE BLAST FURNACE STOVE Filed Aug. 17, 1938 INVENTOR.

Owen R. Rz'ce BY a] MA 7 7 7 166M375.

Patented May 2 1939 UNITED STATES BLAST FURNACE STOVE Owen R. Rice, Chicago,

Ill., assignor to Freyn Engineering Company, Chicago, 111., a. corporation of Maine Application August 1.7, 1938, Serial No. 225,380 3 Claims. (01. 263-19),

The present invention relates to blast furnace stoves.

Regenerative hot blast stoves used for heating the blast for blast furnaces are commonly constructed in the form of cylindrical steel shells containing an open checkerwork of firebrick which alternately receives heat from, the combustion of gases and gives up this heat to the flow of air blast to the furnace.

1 The checkerwork usually consists of firebrick shapes arranged in a formal manner both as to elevation and plan, and are so disposed that all parts of the checkerwork horizontal cross section participates substantially equally in the ab- 15 sorption and discharge of heat according to their respective elevations. That is, the checkers near the outside periphery of the checker structure are substantially just as hot as those nearer the interior of the checker structure.

20 In order to avoid excessive heating of the cylconsists in effect, of a vertical cylinder of flre-.

35 bricks, bonded together with a flreclay mortar.

By reason of its cylindrical construction, it possesses considerable strength for resisting forces directed inwardly toward the center line of the stove. However, it possesses comparatively little strength to resist forces directed outwardly from the center line of the stove. As a structure, in its ordinary utilization, the ring wall is subjected to forces acting outwardly from the center line of the stove, such forces being, for example, the forces developed by horizontal thermal expansion of the checkerwork or by any tendency of the checkerwork to lean outwardly, or to rotate, or, in general, to become displaced. Such forces the ring wall, of itself, is least able to resist. It de- 50 pends for its resistance to such forces upon the metallic stove shell.

From the foregoing, it'will be seen that the actual function of a ring wall is limited to that of an insulator to protect the stove shell from heat.

5 It does not function as a checker structure rendrical metallic shell of the stove, it has been tainer the stove shell itself must back up the ring wall in this function.

The checker structure, considered in any horizontal plane, may have an irregular contour; that is, the cylinder comprising the checker struc- 5 ture may, in any horizontal plane, have a rough or serrated peripheral surface. One of the disadvantages of the bonded brick ring wall is that a great deal of cutting of brick is required to make the ring wall structure conform to the irregular profile of the adjacent checker structure. In operation, the checker structure is subjected to considerable movement due to expansion and contraction during variations in temperature, and the bonded ring wall as heretofore used must it; permit these expansive and contractive movements during the operation of the stove.

An object of the present invention is to provide a stove construction which is relatively cheap to manufacture and emcient in operation.

A further object is to provide a stove construc-. tion in which the expensive ring wall construction is omitted and in its place is provided a stove construction which will protect the cylindrical shell of the stove.

A further object is to provide an improved method of building a blast furnace stove; and

A further object is to provide an improved stove and an improved method for making said stove, well adapted to'meet the needs of commercial service.

Further objects will appear as the description proceeds.

Referring to the drawing- Figure 1 is a horizontal sectional view showing a portion of a stove construction embodying the principles of the present invention, said view showing the stove at an intermediate point in its manufacture; and

Figure 2 is a view similar to Figure 1, but illustrating the present invention in connection with a slightly different checker construction.

In both Figures 1 and 2, the checker assembly is indicated by the numeral 7 l0. Said checker bricks of said assembly are set up in a formal manner to provide a substantially cylindrical construction having, in any plane, a serrated contour. The numeral ll indicates the metallic shell of the stove. Between the exterior contour of the checker assembly and the stove shell II is a wall l2, of insulating material which should be physically of a fairly strong nature. It is suggested to use a poured concrete consisting of high temperature-resistant cement with an aggregate consisting wholly orpin part of granulated slag. ll

Such material will set hard into a monolithic mass having substantial physical strength and resistance to abrasion or pulverization, and yet will have favorable insulating properties. In fact, it will have, per unit of thickness, several times the insulating power of firebrick and will compare favorably with the insulating power of some of the best commercial insulating materials. It will have distinct advantages over the latter in its cost economy and, in its physical strength.-

Moreover, it may be made to conform readily to the general contour of the periphery of the checker structure without the labor and cost of cutting and shaping such as applies to the bonded brick ring wall now commonly used.

According to the present invention, after the checker assembly III has been built up, a sheet of relatively thin volatile material I3 is placed in contact with the peripheral surface of said checker assembly. This thin volatile material may consist of paper, or cardboard, ply wood or equivalent material. The concrete filling I2 is poured between the sheet l3 and the shell ll.

When the stove, constructed as above described, is put into service and subjected to heat, the volatile sheeting l3 between the checker assembly and the concrete I! will totally or for the most part disappear, leaving a distinct and definite region of cleavage between the checker assembly l0 and the adjacent concrete structure, thus allowing the checker structure to "breathe with its alternate acquirement and delivery of heat.

A stove thus constructed without a formal ring wall of firebrick has lost nothing from the structural or thermal standpoint from stoves as heretofore constructed with a firebrick ring wall, and it has gained the advantages of lower cost. According to the present invention, it is possible to place more heat exchanging-checkerwork within the same volume of metallic shell, while still maintaining an insulating value around the stove equivalent to the construction now commonly used. By reason of the use of the sheeting It, the cost of production has been-cut down materially and a clear region of cleavage has been provided to permit relative movement between the checker structure and the insulating material.

Though a preferred embodiment of the present invention has-been described in detail, further modifications may occur to those skilled in the art. It is intended to cover all such modifications as fall within the scope of the appended claims.

What is claimed is:

1. In a blast furnace stove, in combination, a checker construction, a shell wall encircling said checker construction, and a molded insulating wall in contact with the interior surface of said shell wall but spaced peripherally from said checker construction.

2. In a blast furnace stove, in combination, a stove shell, a checker construction coaxially disposed with respect to said stove shell, a sheeting of volatile material encircling said checker construction, and a molded insulating material between the interior surface of said shell wall and the exterior surface of said sheeting.

3. The method of making a blast furnace stove,

which consists in providing a cylindrical shell, a .0

shell and said sheeting, allowing said insulating II material to solidify, and causing said sheeting to disappear by the application of heat thereto.

OWEN R. RICE. 

